A very big company has provided financial consulting services to end-users. It uses the traditional MySQL database inside EC2 t2.medium instances which mainly deal with legacy services. As a business grows, read contention is becoming more and more frequent for the database. The AWS architect suggests using Aurora to scale as it is much cheaper and provides great read scalability. How would you use Aurora to scale up and ease the read contention issue? (Select THREE.)

Answer options:

A.Create an Amazon Aurora MySQL DB db.r5.16xlarge instance. Make sure that Multi-AZ deployment is enabled in different zones. Enable Aurora global tables.
B.Create an Amazon Aurora MySQL DB cluster. The Aurora DB cluster endpoint address will be used when referenced by the MySQL source instances to scale up.
C.Set up replication between a MySQL DB instance and an Amazon Aurora MySQL DB cluster. Monitor the replication to ensure that it remains healthy and repair it if necessary.
D.As Aurora does not support MySQL database running external to Amazon RDS, migrate the database from EC2 MySQL to RDS MySQL first and then use Aurora to scale the database.
E.Make the Aurora DB a replication slave of MySQL DB instances. This applies to the Amazon RDS MySQL DB instance, or a MySQL database running in EC2.
 

Correct Answer – B, C, E
 
Amazon Aurora can be used with the MySQL DB instance to take advantage of the read scaling capabilities of Amazon Aurora and expand the read workload for the MySQL DB instance. To use Aurora to read scale the MySQL DB instance, create an Amazon Aurora MySQL DB cluster and make it a replication slave of your MySQL DB instance. This applies to an Amazon RDS MySQL DB instance, or a MySQL database running external to Amazon RDS.
Please refer to https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora-ug.pdf
One thing to note is that Aurora has the concept of DB cluster and can scale up to 15 read replicas. The below is a screenshot of when DB cluster identifier is defined:
Option A is incorrect: Because it is unnecessary to use db.r5.16xlarge which is not cost-efficient. Also, Multi-AZ deployment is for availability instead of scalability.
Option B is CORRECT: Because an Amazon Aurora MySQL DB cluster needs to be set up first so that the source MySQL database will use its endpoint.
Option C is CORRECT: Because when replication starts, it is important to monitor if the data is successfully synchronized. This is also stated in https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora-ug.pdf
Option D is incorrect: Aurora can scale from the MySQL instances outside of RDS MySQL.
Option E is CORRECT: The same reason as options
D. Refer to “Start Replication Between an External Master Instance and a MySQL DB Instance on Amazon RDS” in https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora-ug.pdf page 575.